Double-acting hot gas multi-cylinder piston engine

ABSTRACT

A group of operating cylinders and regenerating cylinders are located side by side; a similar group is located opposite the first, spaced in V-arrangement, with the pistons all connected to a common crankshaft. The location of cylinders and pistons is such that the rows formed by the groups of cylinders alternately include an operating cylinder and a regenerating cylinder, the cold working space of the end cylinder in a row being connected to the regenerator of the opposite row, and, through the regenerator, to the hot working space of the next adjacent operating cylinder, to provide for short connections between cylinders, with interposed regenerators.

United States Patent Grossman et al.

DOUBLE-ACTING HOT GAS MULTI-CYLINDER PISTON ENGINE Inventors: Joachim Grossman, Augsburg;

Giinter Reuchlein; Eckhard Tusch, both of Gersthofen; Freidemann Zacharias, Augsburg, all of Germany Maschinenfabrik Augsburg-Nurnberg Aktiengesellschaft (M.A.N.), Augsburg; Motorenwerke Mannheim AG, vormals Benz Abteilung Stationarer Motorenbau, Mannheim, both of, Germany Dec. 18, 1972 Assignees:

Filed:

1 Appl. No.: 315,930

Foreign Application Priority Data Dec. 29,1971 Germany 2165332 US. Cl. 60/525 Int. Cl. FOlk 25/08, F03g 7/06 Field of Search 60/525 [56] References Cited UNITED STATES PATENTS 15,771 9/1856 Mc'Donough 60/24 2,590,662 3/1952 Van Weenen 60/24 2,616,245 11/1952 Van Weenen 60/24 3,527,049

9/1970 Bush 60/24 Primary ExaminerEdgar W. Geoghegan Assistant ExaminerH. Burks, Sr. Attorney, Agent, or FirmFlynn & Frishauf [5 7 ABSTRACT A group of operating cylinders and regenerating cylinders are located side by side; a similar group is located opposite the first, spaced in V-arrangement, with the pistons all connected to a common crankshaft. The location of cylinders and pistons is such that the rows formed by the groups of cylinders alternately include an operating cylinder and a regenerating cylinder, the cold working space of the end cylinder in a row being connected to the regenerator of the opposite row, and, through the regenerator, to'the hot working space of the next adjacent operating cylinder, to provide for short connections between cylinders, with interposed regenerators.

13 Claims, 4 Drawing Figures SHEEI 1 O 4 Fig.1

ATENTED APR 9 I974 saw 3 or 4 DOUBLE-ACTING HOT GAS MULTI-CYLINDER PISTON ENGINE The present invention relates to a double-acting hot gas multi-cylinder piston engine and more particularly to this type of engine in which the cylinders are interconnected with an interposed regenerator, re-heater, cooler, or the like.

Hot gas engines have previously been proposed (see German Patent 802,486) in which the cylinders are all arranged in a row. The cylinders have hot and cold operating regions or spaces, and the various regions or spaces within the cylinders are interconnected by ductways with the regions or spaces of adjacent or other cylinders. The ducts, or connecting lines are of different length. The intermediately located cylinders of the row have their first working space, for example the cold working space, connected not to the other working space, for example the hot working space, of an adjacent cylinder, but rather are connected in a specific manner to cylinders which are further removed. The arrangement has asan object to prevent long interconnections which would be undesirable due to the great space requirements and flow losses, as well as heat losses; the arrangement, still, doesnot permit efficient utilization of space, or heat transfer. The arrangement also requires substantial space for the engine unit itself if more than four cylinders are to be used.

It is an object of the present invention to provide a multi-cylinder hot gas piston engine which is so conv SUBJECT MATTER OF THE PRESENT INVENTION Briefly, the cylinders are arranged in two rows, located in V-shaped formation. Each row includes, alternately, an operating cylinder and a regenerator cylinder. One working space, at the end of a cylinder in a row, is connected to the other working space of the closest cylinder in the other row; one working space of that cylinder, and of each further working cylinder is then connected with-the other working space of the adjacent cylinder in the same row; The pistons, operating in all the cylinders, are connected to a common crankshaft, similar to'a V-automotive-type internal combustion engine.

The arrangement has the advantage of compact construction, a simple transfer of reciprocating motion of the piston to an output shaft and effective utilization of heating fuel.

The invention will be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a general, perspective schematic view of the basic construction of a hot gas engine, omitting nonessential parts not necessary to an understanding of the invention, and ancillary equipment;

FIG. 2 is a schematic top view of the structure of FIG. 1, illustrating particularly the interconnection between the working spaces of the cylinder units of the machine;

FIG. 3 is a transverse cross-sectional view through an operating embodiment of the machine of FIG. 1; and

FIG. 4 is a transverse cross-section view through a modified embodiment of an operating structure.

For purposes of illustration, a 6-cylinder engine is shown in FIGS. 1 and 2. It uses six operating cylinders l, 2, 3, 4, 5, 6, and six regenerators 7 12, each of generally cylindrical shape. Regenerators 7 12, together with an associated cooler, or radiator 13 are located in a cylindrical housing, having approximately the same size of the cylinders I-6, and will be referred to hereinafter as cylinder units. Cylinders 1 3 and regenerators 7-9 are located in a row 14; cylinders 4, 5 and 6 and regenerators l0, l1, 12 are located in a row 15, operating cylinders and regenerator cylinders being located alternately, the two rows 14, 15 being inclined with respect to each other and located in a V- arrangement. An operating cylinder in one row, for example cylinder 3 or 6 is located immediately opposite a regenerator cylinder, for example 10, 7, respectively, of the other row.

The cylinders themselves are longitudinally elongated, as best seen in FIG. 3 which illustrates cylinder 6. The other cylinders are similar. A piston 18 reciprocates within the cylinder 6, the piston 18 being connected by a piston rod 20 with a cross slide 21. Cross slide 21 is longitudinally slidable in guide or running surfaces 22. The guide surfaces 22 are secured to a frame 23. Frame 23 extends over the entire length of the motor and supports cylinders 1-6 as well as regenerators 7-12, including the associated radiators. A piston rod 25 is pivoted to a pin 24on the cross slide 21, the other end of piston rod 25 being connected to the crank arm of a crankshaft 26. The' other cylinders are similar and are similarly connected to the main, or

crankshaft26.

fPiston 18 is illustrated at its upper maximum or dead point position. Above the cylinder 18, a hot working space 27 is located; the space 28 beneath the cylinder is a cold working space. As best shown in FIG. 2, the cylinders 1-3 and 5-6 also have hot working spaces 29-33, and cold working spaces 34-38. The hot working space 27 of the end cylinder 6 in row 15 is connected to a manifold 39. Extending from manifold 39 is a plurality of U-shaped tubes to form a flat heating tube assembly 40. The hot working spaces 29-33 of of the other cylinders are likewise connected to heater tubes 41-45.T he ends are connected to a further manifold 46 which forms the connection to the adjacent regenerator 12. As best seen in FIGS. l-3, a manifold, for example manifold 47 associated with a regenerator, for exampleregenerator 7 is located in a plane which is different from the plane of the manifold of an adjacent cylinder, for example manifold 48, The manifolds 39, 48 of all the-cylinders, as well as manifolds 47, 46, for example of all the regenerators are similar. This permits mass production and interchangeability of parts with respect to any specific machine as well as with respect to various types and models of machines, and permits construction of motors of multi-cylinder construction with similar parts, by multiplying the number of parts in a row. Additionally, manufacture of the various parts is simplified. The particular arrangements of manifolds and heater tubes is disclosed and shown in copending application, Ser. No.'3l,7,778 filed 12-22-72. The cold working space 28, 36, respectively of the cylinder 6, 3 respectively, located at the ends of the respective rows is connected over a duct, each, 49, 50, respectively, and a radiator, for example 13, with regenerators 7, 10, respectively, located at the end of the opposite row. The cold working spaces '34, 38 of the further cylinders 1, 2, 4, are connected by means of lines 51-54 to the radiator of the immediately adjacent regenerator 8, 9, 11, 12, respectively. Thus, the hot working space of any one cylinder is connected to the cold working space of an adjacent cylinder over the immediately adjacent regenerator and the associated radiator. This arrangement permits use of only short ducts or lines between the working spaces of the cylinders.

As best seen in FIG. 1, the heater tube assemblies such as 41, 42, 43 of a row, for example row 14, extend inwardly of the V approximately or up to a plane extending through the center of the crankshaft 26, that is, intermediate the angle of the V. They are as wide as the width of a cylinder and an adjacent regenerator, such as cylinders 1 and regenerators 7. The heater tube assemblies 40 to 45 thus completely cover the free space between the two rows 14, 15, to close off the V at the top side thereof.

Heat is supplied to the heater tube assemblies by means of a burner 55 (FIG. 3) located in the space enclosed by the V formed by the two rows 14, 15. An inner combustion chamber 56 and a flame guide or flame duct 57 is associated with burner'55. The flame guide 57 becomes wider at the end remote from burner 55, so that the combustion gases from the burner can completely flow around the heating tubes, such as tube assemblies 40, 41, throughout their full length. After passingthrough the heat exchanger tube assemblies 40,

41, the gases are conducted in direction'of the arrows a into a pre-heater unit formed of tubes 58, 59, to be then collected in exhaust manifolds 60, 61. Fresh air is supplied through inlet ducts 62, 63, and in counterflow (forexample through pipes in the plane of the drawing of FIG. 3, but axially with respect to shaft 26 offset) to be then collected ina pre-heater collection manifold 64. At the end of the motor, the collection manifold ,64 is connected'to a pair of air distribution ducts 65, 66, each of which is formed with openings 67, 68 to supply the preheated combustion air from the outside to the flame guide duct 57. The pre-heated air 'then flows along the outer wall of the flame duct 57 and is admitted through opening 69 as primary air into the combustion chamber 56, or as secondary air through opening 70 into the flame duct or guide 57.

The construction permitsshort paths between theworking spaces of the cylinders and additionally a desira'ble space utilization of the entire space required by the assembly of operating cylinders and regenerating to the other end of the tubes of a heater tube group, or

cylinders and radiators, to thus provide a compact exbe interchanged with respect to'each-other, but if this is done, however, manifolds must be formed for thecylinders and regenerators located at the end of any specific row-which differ from the manifolds of the remaining cylinders and regenerators. I

The embodiment of FIG. 4 illustrates a pair of V- inclined cylinder and regenerator rows. The cylindersand the regenerator cylinder units 81, or regenerators, with subsequent coolers, arelojcated in V-arranged inclined rows, operating cylinders and regenerator cylinder' units being alternately located. Cylinder is formed with a manifold 83 which provides the connection'to one end of the tubes of a heater tube assembly 84, formed of a group of heater tubes. Similarly, regenerator 81 is connected to a manifold 85 which connects assembly 86. The two heater tube assemblies 84, 86 are located in a single plane. A flame guide 87 is located above the heater tube assemblies 84, 86 which merges into a combustion chamber 88. A burner 89 is located at the upper tip of combustion chamber 88. Locating the two heater tube groups 84, 86 in a plane provides for uniform heat application to all heater tubes in a simple construction, so that all heater tubes are uniformly subjected to hot gases from the burner. Air pre-heater ducts 90, 91 are located above the cylinders 80 and the regenerators 81, extending over the entire length of the motor. Air needed for combustion enters through the ducts 92, 93 into the pre-heaters 90, 91 and flows downwardly therethrough. Openings 94, 95 connect the pre-heater ducts 90, 9 1 to ducts 96. 97 which are defined on the one hand by fixed structural elements of the pre-heaters 90, 91 and on the other by the flame guide 87 and the combustion chamber 88. Air flows through the ducts 96, 97 into combustion chamber 88 through openings 98. The combustion gases, after passing through the heater tubes 84, 86 are directed by a deflection plate 99 to a gap, not shown, between the operating and regenerator cylinders into manifolds 100, 101 formed in the housing, to then pass, in counterflow with respect to the incoming air in pre-heater 90, 91 to outlet collection ducts 102, 103.

Even if the burner is separate from the engine itself, as in FIG. 4, the'overall size of the engine or motor can be held to be small, so that the space utilization is. efficient and to provide for a compact engine.

Various changes and modifications may be made, and the features described in connection with any one embodiment may be applied to other embodiments, within the inventive concept. The construction illustrated specifically in connection with FIG. 3 provides a very small, compact engine, in which the groups or assemblies of heater tubes are uniformly subjected to heat transfer, being heated by the flames, or combustion gases of one, or. a plurality of burners. A single burner can be used to provide heat for the heater tube groups of a pair of oppositely located cylinders, that is, of the cylinders of different rows, so that a smaller number of burner units or burner elements can be used to heat a given number of heater tubes. If more heat should be applied to the heater tubes than can be obtained from burners which can be located in the V- shaped space, then thearrangement-described in connection with FIG. 4 is suitable, particularly if a preheater is used, and the burnersare located between the pre-heaters themselves. Counterflow arrangement of i the pre-heaters has the additional advantage that the a plgrality qf cylindricalregenerators (7-12) the cylinders being arranged in two rows .(14, 1 5) relatively located in V formation, each row ineluding, alternately, one operating cylinder (1-6) and a regenerator cylinder (7-12) and any operating cylinder in a row being placed opposite a regenerator cylinder in the other row;

the cold working space (28, 36) of the end cw inders (3, 6) in the rows (14, being connected (50, 49) to the regenerators (10, 7) located opposite the respective cylinders (3, 6) at the ends of the other respective rows, the cold working space (34, 35, 37, 38) of the other cylinders of the respective rows being connected (51, 52, 53, 54) to the inlets of the remaining regenerator cylinders t (8, 9, 11, 12) located adjacent the respective other cylinders in the respective rows,

a plurality of heat exchange means (40-45; 84, 86), one for each cylinder-regenerator pair located in the space bridging the open ends of the V of the V-formation and comprising a plurality of groups of heat exchange tubes located to essentially close off the open ends of the V formation;

the outlets of the respective regenerators (7-l2 being connected over respective heat exchange means (40-45; 84, 86) to the hot working spaces (27, 29-32) of adjacently located cylinders (1-6)' of the respective rows;

a common crankshaft (26);

and means (20, 25) connecting the pistons of eachsaid operating sxliqdetat said ks a I TEng ine according to claim 1, wherein the heat exchange means comprises a plurality of groups of heat exchange tubes, each group extending, in axial direction, from the upper end of the respective regenerator cylinder essentially over the width thereof and the width exchange means (84, 86).

of the adjacently connected operating cylinder.

rows (14, 15).

relation to the first duct means to pre-heat air contained therein, and means conducting the preheated air as combustion supportmg air to the heater means.

8. Engine according to claim 7, wherein the duct means are arranged so that the combustion gases and the air to be pre-heated are conducted in counterflow direction.

9. Engine according to claim 5, wherein the heat exchange means'is located in the space bridging the open ends of the V of the V-formation and wherein the he ater means (89) areiaetia a'aava the heat 10. Engine according to claim 9,-wherein the heater means comprises a burner (89);

air pre-heat means 90, 91) are provided located above the rows of the cylinders (14, 15) and subjected to exhaust gases from the burner;

and flame directing means (87) are provided,

directing flames trom the burner and immediately arising gases unto the heat exchange means and separating the immediately arising combustion gases from the air to be supplied to the burner. 11. Engine according to claim 10, wherein the flame directing means comprises a substantially inverted V-shaped shield, the burner being located substantially at the apex of the V;

and air intake means (90, 91) are provided leading to the lower portions outside of the flame directing shield, and then upwardly along the shield to the burner to provide an air pre-heat path for combustion air and to cool the shield. 

1. Double-acting hot gas multi-cylinder piston engine comprising a plurality of operating cylinders (1-6), each having a hot working space (27, 29, 30, 31, 32) on one side of the piston and a cold working space (28, 34, 35, 36, 37, 38) at the other side of the piston; a plurality of cylindrical regenerators (7-12), the cylinders being arranged in two rows (14, 15) relatively located in V formation, each row including, alternately, one operating cylinder (1-6) and a regenerator cylinder (7-12), and any operating cylinder in a row being placed opposite a regenerator cylinder in the other row; the cold working space (28, 36) of the end cylinders (3, 6) in the rows (14, 15) being connected (50, 49) to the regenerators (10, 7) located opposite the respective cylinders (3, 6) at the ends of the other respective rows, the cold working space (34, 35, 37, 38) of the other cylinders of the respective rows being connected (51, 52, 53, 54) to the inlets of the remaining regenerator cylinders (8, 9, 11, 12) located adjacent the respective other cylinders in the respective rows, a plurality of heat exchange means (40-45; 84, 86), one for each cylinder-regenerator pair located in the space bridging the open ends of the V of the V-formation and comprising a plurality of groups of heat exchange tubes located to essentially close off the open ends of the V formation; the outlets of the respective regenerators (7-12) being connected over respective heat exchange means (40-45; 84, 86) to the hot working spaces (27, 29-32) of adjacently located cylinders (1-6) of the respective rows; a common crankshaft (26); and means (20, 25) connecting the pistons of each said operating cylinders to said crankshaft.
 2. Engine according to claim 1, wherein the heat exchange means comprises a plurality of groups of heat exchange tubes, each group extending, in axial direction, from the upper end of the respective regenerator cylinder essentially over the width thereof and the width of the adjacently connected operating cylinder.
 3. Engine according to claim 1, wherein the heat exchange means connected to the cylinders of one row are located in essentially a single plane.
 4. Engine according to claim 3, wherein the heat exchange means (FIG. 4: 84, 86) of both rows are located in a common plane.
 5. Engine according to claim 1, further comprising at least one heater means (55, 89) located to direct heat to the heat exchange means of at least two oppositely located operating cylinders (1, 6) in opposite rows (14, 15).
 6. Engine according to claim 5, wherein the heater means (55) is located in the space included by the V of the V-formation.
 7. Engine according to claim 5, wherein the heat exchange means (40-45; 84, 86) is located in the space bridging the open ends of the V of the V-formation; the heater means comprises a burner; and air pre-heater means are provided located above the heat exchange means and comprising a first duct means (58, 59, 60, 61) collecting combustion gases from the heater means (55), a second duct means (62, 63, 64) in heat exchange relation to the first duct means to pre-heat air contained therein, and means conducting the pre-heated air as combustion supporting air to the heater means.
 8. Engine according to claim 7, wherein the duct means are arranged so that the combustion gases and the air to be pre-heated are conducted in counterflow direction.
 9. Engine according to claim 5, wherein the heat exchange means is located in the space bridging the open ends of the V of the V-formation and wherein the heater means (89) are located above the heat exchange means (84, 86).
 10. Engine according to claim 9, wherein the heater means comprises a burner (89); air pre-heat means (90, 91) are provided located above the rows of the cylinders (14, 15) and subjected to exhaust gases from the burner; and flame directing means (87) are provided, directing flames from the burner and immediately arising gases unto the heat exchange means and separating the immediately arising combustion gases from the air to be supplied to the burner.
 11. Engine according to claim 10, wherein the flame directing means comprises a substantially inverted V-shaped shield, the burner being located substantially at the apex of the V; and air intake means (90, 91) are provided leading to the lower portions outside of the flame directing shield, and then upwardly along the shield to the burner to provide an air pre-heat path for combustion air and to cool the shield. 